Novel Selective Inhibitors of Ubiquitin Specific Protease 7, the Pharmaceutical Compositions Thereof and Their Therapeutic Applications

ABSTRACT

The present invention concerns the discovery of new selective inhibitors of ubiquitin specific proteases, their process of preparation and their therapeutic use.

The present invention concerns the discovery of new selective inhibitors of ubiquitin specific proteases, their process of preparation and their therapeutic use.

Ubiquitin specific proteases (USP) are cysteines proteases which belong to the deubiquitinylation enzymes (DUBs) family.

Deregulation of the ubiquitin-proteasome system has been implicated in the pathogenesis of many human diseases, including cancer (Hoeller et al. Nat Rev Cancer 2006, 6(10), 776-788), neurodegenerative disorders (Rubinsztein, Nature 2006, 443(7113), 780-786) and viral diseases (Gao & Luo Can J Physiol Pharmacol 2006, 84(1), 5-14). The market success of the proteasome inhibitor Velcade® (bortezomib) for the treatment of multiple myeloma and mantle cell lymphoma has established this system as a valid target for cancer treatment (Adams, Nat Rev Cancer 2004, 4(5), 349-360). A promising alternative to targeting the proteasome itself would be to interfere with the upstream ubiquitin conjugation/deconjugation machinery, to generate more specific, less toxic anticancer agents.

Mono- and polyubiquitination can be reversed by deubiquitinating enzymes, which specifically cleave the isopeptide bond at the C-terminus of ubiquitin. Ubiquitin specific proteases and ubiquitin C-terminal hydrolases (UCH) enzymes are the best characterized members of the DUB family (Komander et al. Nat. Rev. Mol. Cell. Biol. 2009, 10(8), 550-63; Nijman et al. Cell 2005, 123(5), 773-786). UCHs are thought to cleave small protein substrates preferentially and to be involved principally in the processing and recycling of ubiquitin, but their specific functions remain poorly understood. USPs constitute the largest subfamily of DUBs, with more than 60 members. They remove ubiquitin from specific protein substrates, thus preventing their targeting to the proteasome or regulating their subcellular localization and activation (Daviet & Colland, Biochimie 2008, 90(2), 270-83). USPs are emerging as potential targets for pharmacological interference with the ubiquitin regulation machinery, based on their protease activity and involvement in several human diseases.

USP7 (Ubiquitin Specific Protease 7)/HAUSP (Herpes Associated Ubiquitin Specific Protease) is a 135 kDa protein of the USP family. USP7 has been shown to interact with viral proteins, such as ICP0 (Vmw 110), a herpes simplex virus immediate-early gene stimulating initiation of the viral lytic cycle (Everett et al., J Virol 73, 1999, 417-426), and EBNA1 (Epstein-Barr Nuclear Antigen-1) (Holowaty et al., J Biol Chem 2003, 278, 29987-29994 and 47753-47761). Human proteins, such as p53 and the major E3 ligase of p53, Mdm2, have also been identified as partners and substrates of USP7 (Cummins et al. Nature 2004, 486, Cummins & Vogelstein, Cell Cycle, 2004, 3, 689-692; Li et al. Mol Cell 2004, 13, 879-886; Li et al. Nature 2002, 416, 648-653). More generally USP7 can deubiquitinate different targets, including Mdm2 and p53, and the net deubiquitination of these latter targets ultimately determines functional p53 levels. Consistent with recent reports, USP7 silencing has also been shown to increase steady-state p53 levels by promoting Mdm2 degradation. More recently, both upregulation and downregulation of USP7 have been shown to inhibit colon cancer cell proliferation in vitro and tumor growth in vivo, by resulting in constitutively high p53 levels (Becker et al. Cell Cycle 2008, 7(9), 1205-13.

USP7 has also been shown in human cells to deubiquitinate the well-known tumor suppressor gene PTEN, which provokes its nuclear export and hence its inactivation (Song et al., Nature 2008, 455(7214), 813-7). More importantly, USP7 overexpression was reported for the first time in prostate cancer and this overexpression was directly associated with tumour aggressiveness (Song et al., Nature 2008, 455(7214), 813-7).

USP7 has also been shown in human cells to deubiquitinate FOXO4, which provokes its nuclear export and hence its inactivation; consequently the oncogenic PI3K/PKB signaling pathway was activated (van der Horst et al., Nat Cell Biol. 2006, 8, 1064-1073) Finally, USP7 plays an important role in p53-mediated cellular responses to various types of stress, such as DNA damage and oxidative stress (Marchenko et al., Embo J. 2007 26, 923-934, Meulmeester et al. Mol Cell 2005, 18, 565-576., van der Horst et al., Nat Cell Biol. 2006, 8, 1064-1073).

Synthetic inhibitors of USP7 protein binding containing the polypeptide portion P¹-Gly-P³-Ser, where P¹ is a glutamic acid residue or an amino acid with a non polar side chain and P³ is a glycine residue or an amino acid with non polar side chain, have been reported (WO2006072048).

The phenotypes associated with USP7 silencing and the known connections between USP7 and essential viral proteins and oncogenic pathways, such as the p53/Mdm2 and PI3K/PKB pathways, strongly suggest that targeting USP7 with small-molecule inhibitors may be beneficial in the treatment of cancers and viral diseases.

An inhibitor against USP7 was recently reported (Colland et al. Molecular Cancer Therapeutics 2009, 8, 2286-95 and EP 1 749 822).

However, to date, no specific USP7 small molecule inhibitors seem to have been reported.

According to a first object, the present invention concerns a compound of formula (I):

-   -   wherein:

i is an integer chosen from 0, 1, 2 or 3 when n is 1, or from 0, 1, 2, 3 or 4 when n is 2, or from 0, 1, 2, 3, 4 or 5 when n is 3;

j is an integer chosen from 0, 1, 2 or 3;

k is an integer chosen from 0 or 1;

n and n′ identical or different are integers chosen from 0, 1, 2 or 4, provided that 2≦n+n′≦4;

Z is CH₂<, —HC<, —N<, NH< or O<;

each Ri located on any available position of the A ring is identical or different and chosen from halogen, alkyl, aryl, -alkylaryl, OR, NRR′, CN, CF₃, COR, COOR, CONRR′;

-   -   each Rj located on any available position of the C ring is         identical or different and chosen from halogen, alkyl, aryl,         -alkylaryl, OR, NRR′, CN, COR, COOR, CONRR′;

each Rk, identical or different, is independently chosen from halogen, alkyl, alkoxy, cyano;

X is chosen from H, alkyl, aryl, -alkylaryl, wherein said alkyl and/or aryl is optionally substituted by halogen, alkyl, CN, CF₃, OR, NRR′, COR, COOR, CONRR′;

Y is chosen from:

-   -   (CHT)_(p)NRaRb where         -   Ra and Rb, identical or different, are independently chosen             from H, alkyl, aryl or arylalkyl, wherein said aryl is             optionally substituted by halogen, alkyl, CN, CF₃, ═O, OR,             NRR′, COR, COOR, CONRR′;         -   or Ra and Rb together form with the N atom to which they are             attached a N comprising 5 to 7-membered heterocycle which             may comprise one or two more heteroatoms chosen from N, O or             S, said heterocycle being optionally substituted by one or             more of halogen; ═O; alkyl; -alkylaryl or aryl wherein said             aryl is optionally substituted by halogen; CN; CF₃; OR;             NRR′; COR; COOR; CONRR′;         -   p is an integer chosen from 0 to 6;         -   each T, identical or different is independently chosen from             H or alkyl.

-   -   -    wherein:

-   -   -    is a saturated or partially unsaturated heterocycle or             heteroaryl, mono or bicyclic, comprising 1, 2 or 3             heteroatom(s) chosen from N, O or S, optionally substituted             by one or more of alkyl; -alkylaryl; OR; C(═O)OR; ═O; CN;             CF₃; COR; NRR′; CONRR′; aryl or -alkylaryl wherein said aryl             is optionally substituted by alkyl, halogen, OR or COR;         -   q is an integer chosen from 0 to 6;         -   each T, identical or different is independently chosen from             H or alkyl.

    -   (CHT)_(r)-aryl wherein:         -   said mono or bicyclic aryl is optionally substituted by one             or more of alkyl; OR; CF₃, SO₂NRR′; —C(═O)—R; Halogen; CN;             —NRR′; CONRR; C(═O)—Oalkyl wherein said alkyl is optionally             substituted by NRR′; and/or said mono or bicyclic aryl is             optionally fused with a monocyclic 5 to 7 membered             heterocycle;         -   r is an integer chosen from 0 to 6;         -   each T, identical or different is independently chosen from             H or alkyl;

    -   —(CHT)_(s)-(C3-C7)cycloalkyl where         -   s is an integer chosen from 0 to 6;         -   each T, identical or different is independently chosen from             H or alkyl;         -   said cycloalkyl is monocyclic, or fused with an aryl;

    -   alkyl optionally substituted by CN, Oalkyl;

    -   U-S(O)_(t)-alkyl where         -   t is an integer chosen from 0, 1 or 2;         -   -U- is an alkylene optionally substituted by one or more of             OR; ═O; CF₃ SO₂NRR′; —C(═O)—R; Halogen; CN; —NRR′; CONRR;             C(═O)OR;

or X and Y together form with the N atom to which they are attached an heterocycle comprising said N atom and optionally one or two more heteroatoms, said heterocyle being optionally insaturated and/or

-   -   being optionally substituted by one or more of: ═O; Hal, CN,         NRR′, C(═O)alkyl, alkyl; cycloalkyl; heterocycle; C(═O)—Oalkyl;         aryl or -alkylaryl where said aryl is optionally fused with an         heterocycle and/or said aryl being optionally substituted by         alkyl or COalkyl;     -   being optionally fused with an aryl;         where R and R′, identical or different are independently chosen         from H, alkyl, aryl, -alkylaryl,         or a tautomer thereof, and/or a pharmaceutically acceptable salt         thereof.

The formula (I) of the invention refers to any of the following embodiment or any of their combinations.

According to a particular embodiment, formula (I) does not encompass those compounds where Hal is Cl, i=j=0, and

n′=1, n=1, X is H or a C1-2alkyl and Y is a phenyl optionally substituted by one or two C1-C2alkyl, or

n′=1, n=2, and:

-   -   X is H and Y is a phenyl substituted by CN or —C(═O)CH₃; or     -   X and Y together form a piperazinyl ring substituted by a         methoxyphenyl or fluorophenyl; or     -   X and Y together form a piperidyl ring substituted by a         piperidyl; or     -   one of X is H and Y is a piperidyl substituted with COOEt.

In particular, compounds of the invention may be of the following formula:

where Hal is chosen from F, Cl, Br or I.

Particular compounds are those of formula (I), wherein:

i=j=0; and/or

X is chosen from H, alkyl optionally substituted by CN.

In particular, the A ring is chosen from:

Preferably, n′ is 0, 1 or 2 and n is 3, 2 or 1.

In particular, in formula (I), n′ is 1 and n is 2.

According to an embodiment, Hal is F, Br or I.

According to a further embodiment:

X is defined as above and Y is chosen from:

-   -   (CH₂)_(p)NRaRb where         -   Ra and Rb, identical or different, are independently chosen             from H, alkyl, aryl, -alkylaryl, wherein said aryl is             optionally substituted by alkyl;         -   p is 0, 1, 2 or 3.     -   or where         -   Ra and Rb together form with the N atom to which they are             attached a 5 to 7-membered heterocycle optionally comprising             one or two more heteroatoms chosen from N, O or S, said             heterocycle being optionally substituted by one or more of             halogen; ═O; alkyl; -alkylaryl or aryl where aryl is             optionally substituted by halogen; ═O; CN; CF₃; OR; NRR′;             COR; COOR; CONRR′ and;         -   p is chosen from 2 or 3;

-   -   -    wherein:

-   -   -    is a bicyclic saturated or partially unsaturated             heterocycle or heteroaryl, comprising 1, 2 or 3             heteroatom(s) chosen from N, O or S, optionally substituted             by one or more of alkyl; OR; C(═O)OR; aryl or -alkylaryl             wherein said aryl is optionally substituted by alkyl,             halogen, OR or COR;         -   q is an integer chosen from 0, 1, 2 or 3;         -   each T, identical or different is independently chosen from             H or alkyl;

(CHT)_(r)-aryl wherein:

-   -   said aryl is mono or bicyclic, optionally substituted by one or         more of alkyl, OR, SO₂NRR′; —C(═O)—R; Halogen; CN; C(═O)—Oalkyl,         wherein said alkyl is optionally substituted by NRR′; and said         aryl is optionally fused with an heterocycle;     -   r is an integer chosen from 0, 1, 2 or 3;     -   each T, identical or different is independently chosen from H or         alkyl;         or

X and Y together form with the N atom to which they are attached an heterocycle comprising said N atom and optionally one or two more heteroatoms, said heterocyle being optionally insaturated and/or

-   -   being optionally substituted by one or more of: ═O; alkyl;         cycloalkyl; heterocycle; C(═O)—Oalkyl; aryl or -alkylaryl where         said aryl is optionally substituted by alkyl;     -   being optionally fused with an aryl;         where, preferably, q is 1, 2 or 3, r is 1, 2 or 3.

More particularly, in formula (I):

n′=1 and n=2 or 3;

X is defined as above and Y is chosen from:

-   -   —(CHT)_(p)NRaRb where         -   Ra and Rb, identical or different, are independently chosen             from H, alkyl, aryl, -alkylaryl, wherein said aryl is             optionally substituted by halogen, alkyl, CN, CF₃, OR, NRR′,             COR, COOR, CONRR′;         -   or Ra and Rb together form with the N atom to which they are             attached a N comprising 5 to 7-membered heterocycle             optionally comprising one or two more heteroatoms chosen             from N, O or S, said heterocycle being optionally             substituted by one or more of halogen; alkyl; -alkylaryl or             aryl wherein said aryl is optionally substituted by halogen;             ═O; CN; CF₃; OR; NRR′; COR; COOR; CONRR′;         -   p is an integer chosen from 2 or 3;         -   each T, identical or different is independently chosen from             H or alkyl; or

-   -   -    wherein:

-   -   -    is saturated or partially unsaturated heterocycle or             heteroaryl, mono or bicyclic, comprising 1, 2 or 3             heteroatom(s) chosen from N, O or S, optionally substituted             by one or more of alkyl; -alkylaryl; OR; C(═O)OR; ═O; CN;             CF₃; COR; NRR′; CONRR′; aryl; wherein said aryl is             optionally substituted by alkyl, halogen, OR, COR;         -   q is 1, 2 or 3;         -   each T, identical or different is independently chosen from             H or alkyl;

or X and Y together form with the N atom to which they are attached an heterocycle comprising said N atom and optionally one or two more heteroatoms, said heterocyle being optionally insaturated and/or

-   -   being optionally substituted by one or more of: ═O; alkyl;         cycloalkyl; C(═O)—Oalkyl; -alkylaryl where said aryl is         optionally fused with an heterocycle and/or said aryl being         optionally substituted by alkyl or COalkyl;     -   being optionally fused with an aryl;         where R and R′, identical or different are independently chosen         from H, alkyl, aryl, -alkylaryl.

More preferably in formula (I):

n′=1, n=2 or 3;

X is chosen from H, alkyl, aryl, -alkylaryl, wherein said alkyl and/or aryl is optionally substituted by halogen, alkyl, CN, CF₃, OR, NRR′, COR, COOR, CONRR′;

and Y is chosen from:

-   -   (CHT)_(p)NRaRb where         -   Ra and Rb, identical or different, are independently chosen             from H, alkyl, aryl, -alkylaryl, wherein said aryl is             optionally substituted by halogen, alkyl, CN, CF₃, OR, NRR′,             COR, COOR, CONRR′;         -   p is 1, 2 or 3.

According a specific embodiment, those compounds of formula (I) are chosen from:

-   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [1-(3-methyl-benzyl)-piperidin-4-ylmethyl]-amide -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (1-ethyl-pyrrolidin-2-ylmethyl)-amide -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (2-dipropylamino-ethyl)-amide -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [2-(butyl-ethyl-amino)-ethyl]-amide -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [3-(benzyl-ethyl-amino)-propyl]-amide -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (3-dipropylamino-propyl)-amide -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (2-diethylamino-ethyl)-amide -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (3-pyrrolidin-1-yl-propyl)-amide -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [3-(2,6-dimethyl-piperidin-1-yl)-propyl]-amide -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (3-diethylamino-propyl)-amide -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (2-dimethylamino-ethyl)-amide -   Azepan-1-yl-(9-chloro-5,6,7,8-tetrahydro-acridin-3-yl)-methanone -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [3-(4-propyl-piperazin-1-yl)-propyl]-amide -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [3-(benzyl-methyl-amino)-propyl]-amide -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [3-(4-methyl-piperazin-1-yl)-propyl]-amide -   [1,4′]Bipiperidinyl-1′-yl-(9-chloro-5,6,7,8-tetrahydro-acridin-3-yl)-methanone -   9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (3-morpholin-4-yl-propyl)-amide     or a tautomer thereof, and/or a pharmaceutically acceptable salt     thereof.

As used hereabove or hereafter:

“Alkyl” means an aliphatic hydrocarbon group which may be straight or branched having 1 to 20 carbon atoms in the chain. Preferred alkyl groups have 1 to 12 carbon atoms in the chain. “Branched” means that one or more lower alkyl groups such as methyl, ethyl or propyl are attached to a linear alkyl chain. Exemplary alkyl groups include methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, n-pentyl, 3-pentyl, octyl, nonyl, decyl.

As used herein, the term “cycloalkyl” refers to an aromatic or non aromatic hydrocarbon mono, bi or multi cyclic ring of 3 to 10 carbon atoms formed by the removal of one hydrogen atom. A designation such as “C₅-C₇ cycloalkyl” refers to a cycloalkyl radical containing from 5 to 7 carbon atoms. Examples include cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, etc. as well as the systems formed by their condensation or by the condensation with a phenyl group.

“Alken” means an aliphatic hydrocarbon group containing a carbon-carbon double bond and which may be straight or branched having 2 to 15 carbon atoms in the chain. Preferred alkenyl groups have 2 to 12 carbon atoms in the chain; and more preferably about 2 to 4 carbon atoms in the chain. Exemplary alkenyl groups include ethenyl, propenyl, n-butenyl, i-butenyl, 3-methylbut-2-enyl, n-pentenyl, heptenyl, octenyl, nonenyl, decenyl.

“Halogen atom” refers to fluorine, chlorine, bromine or iodine atom; preferably fluorine and chlorine atom.

“Perhalogenoalkyl” refers to an alkyl group as defined above where all H atoms are replaced by halogen atoms.

“Polyhalogenoalkyl” refers to an alkyl group as defined above where one or more H atoms are replaced by halogen atoms.

“Aryl” means an aromatic monocyclic or multicyclic hydrocarbon ring system of 6 to 14 carbon atoms, preferably of 6 to 10 carbon atoms. Exemplary aryl groups include phenyl or naphthyl.

As used herein, the terms “heterocycle” or “heterocyclic” refer to a saturated, partially unsaturated or unsaturated, non aromatic stable 3 to 14, preferably 5 to 10-membered mono, bi or multicyclic rings wherein at least one member of the ring is a hetero atom. Typically, heteroatoms include, but are not limited to, oxygen, nitrogen, sulfur, selenium, and phosphorus atoms. Preferable heteroatoms are oxygen, nitrogen and sulfur.

Suitable heterocycles are also disclosed in The Handbook of Chemistry and Physics, 76^(th) Edition, CRC Press, Inc., 1995-1996, p. 2-25 to 2-26, the disclosure of which is hereby incorporated by reference.

Preferred non aromatic heterocyclic include, but are not limited to pyrrolidinyl, pyrazolidinyl, imidazolidinyl, oxiranyl, tetrahydrofuranyl, dioxolanyl, tetrahydro-pyranyl, dioxanyl, dioxolanyl, piperidyl, piperazinyl, morpholinyl, pyranyl, imidazolinyl, pyrrolinyl, pyrazolinyl, thiazolidinyl, tetrahydrothiopyranyl, dithianyl, thiomorpholinyl, dihydro-pyranyl, tetrahydropyranyl, dihydropyranyl, tetrahydro-pyridyl, dihydropyridyl, tetrahydropyrimidinyl, dihydrothiopyranyl, azepanyl, as well as the fused systems resulting from the condensation with a phenyl group.

As used herein, the term “heteroaryl” or aromatic heterocycles refers to a 5 to 14, preferably 5 to 10-membered aromatic hetero, mono-, bi- or multicyclic ring. Examples include pyrrolyl, pyridyl, pyrazolyl, thienyl, pyrimidinyl, pyrazinyl, tetrazolyl, indolyl, quinolinyl, purinyl, imidazolyl, thienyl, thiazolyl, benzothiazolyl, furanyl, benzofuranyl, 1,2,4-thiadiazolyl, isothiazolyl, triazoyl, tetrazolyl, isoquinolyl, benzothienyl, isobenzofuryl, pyrazolyl, carbazolyl, benzimidazolyl, isoxazolyl, pyridyl-N-oxide, as well as the fused systems resulting from the condensation with a phenyl group.

“Alkyl”, “alkenyl”, “cycloalkyl”, “aryl”, “heteroaryl”, “heterocycle” and the likes refers also to the corresponding “alkylene”, “alkenylene”, “cycloalkylene”, “arylene”, “heteroarylene”, “heterocyclene” and the likes which are formed by the removal of two hydrogen atoms.

As used herein, the term “patient” refers to either an animal, such as a valuable animal for breeding, company or preservation purposes, or preferably a human or a human child, which is afflicted with, or has the potential to be afflicted with one or more diseases and conditions described herein.

As used herein, a “therapeutically effective amount” refers to an amount of a compound of the present invention which is effective in preventing, reducing, eliminating, treating or controlling the symptoms of the herein-described diseases and conditions. The term “controlling” is intended to refer to all processes wherein there may be a slowing, interrupting, arresting, or stopping of the progression of the diseases and conditions described herein, but does not necessarily indicate a total elimination of all disease and condition symptoms, and is intended to include prophylactic treatment.

As used herein, the expression “pharmaceutically acceptable” refers to those compounds, materials, excipients, compositions or dosage forms which are, within the scope of sound medical judgment, suitable for contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response or other problem complications commensurate with a reasonable benefit/risk ratio.

As used herein, “pharmaceutically acceptable salts” refer to derivatives of the disclosed compounds wherein the parent compound is modified by making acid or base salts thereof. The pharmaceutically acceptable salts include the conventional non-toxic salts or the quaternary ammonium salts of the parent compound formed, for example, from non-toxic inorganic or organic acids. For example, such conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the like, including mono, di or tri-salts thereof; and the salts prepared from organic acids such as acetic, propionic, succinic, tartaric, citric, methanesulfonic, benzenesulfonic, glucoronic, glutamic, benzoic, salicylic, toluenesulfonic, oxalic, fumaric, maleic, lactic and the like. Further addition salts include ammonium salts such as tromethamine, meglumine, epolamine, etc., metal salts such as sodium, potassium, calcium, zinc or magnesium.

The pharmaceutically acceptable salts of the present invention can be synthesized from the parent compound which contains a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two. Generally, non-aqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. Lists of suitable salts are found in Remington's Pharmaceutical Sciences, 20^(th) ed., Mack Publishing Company, Easton, Pa., 2000, the disclosure of which is hereby incorporated by reference.

The compounds of the general formula (I) having geometrical and stereoisomers are also a part of the invention.

According to a further object, the present invention is also concerned with the process of preparation of the compounds of formula (I).

The compounds and process of the present invention may be prepared in a number of ways well-known to those skilled in the art. The compounds can be synthesized, for example, by application or adaptation of the methods described below, or variations thereon as appreciated by the skilled artisan. The appropriate modifications and substitutions will be readily apparent and well known or readily obtainable from the scientific literature to those skilled in the art.

In particular, such methods can be found in R. C. Larock, Comprehensive Organic Transformations, Wiley-VCH Publishers, 1999.

It will be appreciated that the compounds of the present invention may contain one or more asymmetrically substituted carbon atoms, and may be isolated in optically active or racemic forms. Thus, all chiral, diastereomeric, racemic forms, isomeric forms of a structure are intended, unless the specific stereochemistry or isomeric form is specifically indicated. It is well-known in the art how to prepare and isolate such optically active forms. For example, mixtures of stereoisomers may be separated by standard techniques including, but not limited to, resolution of racemic forms, normal, reverse-phase, and chiral chromatography, preferential salt formation, recrystallization, and the like, or by chiral synthesis either from chiral starting materials or by deliberate synthesis of target chiral centers.

Additionally, the process of the invention may lead to several regioisomers which are all encompassed by the present invention. Regioisomers are generally isolated by chromatography.

Compounds of the present invention may be prepared by a variety of synthetic routes. The reagents and starting materials are commercially available, or readily synthesized by well-known techniques by one of ordinary skill in the arts. All substituents, unless otherwise indicated, are as previously defined.

In the reactions described hereinafter, it may be necessary to protect reactive functional groups, for example hydroxyl, amino, imino, thio or carboxy groups, where these are desired in the final product, to avoid their unwanted participation in the reactions. Conventional protecting groups may be used in accordance with standard practice, for examples see T. W. Greene and P. G. M. Wuts in Protective Groups in Organic Chemistry, 3^(rd) ed., John Wiley and Sons, 1999; J. F. W. McOmie in Protective Groups in Organic Chemistry, Plenum Press, 1973.

Some reactions may be carried out in the presence of a base. There is no particular restriction on the nature of the base to be used in this reaction, and any base conventionally used in reactions of this type may equally be used here, provided that it has no adverse effect on other parts of the molecule. Examples of suitable bases include: sodium hydroxide, potassium carbonate, triethylamine, alkali metal hydrides, such as sodium hydride and potassium hydride; alkyllithium compounds, such as methyllithium and butyllithium; and alkali metal alkoxides, such as sodium methoxide and sodium ethoxide.

Usually, reactions are carried out in a suitable solvent. A variety of solvents may be used, provided that it has no adverse effect on the reaction or on the reagents involved. Examples of suitable solvents include: hydrocarbons, which may be aromatic, aliphatic or cycloaliphatic hydrocarbons, such as hexane, cyclohexane, benzene, toluene and xylene; amides, such as dimethylformamide; alcohols such as ethanol and methanol and ethers, such as diethyl ether and tetrahydrofuran.

The reactions can take place over a wide range of temperatures. In general, it is found convenient to carry out the reaction at a temperature of from 0° C. to 150° C. (more preferably from about room temperature to 100° C.). The time respired for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the reagents. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from 3 hours to 20 hours will usually suffice.

The compound thus prepared may be recovered from the reaction mixture by conventional means. For example, the compounds may be recovered by distilling off the solvent from the reaction mixture or, if necessary, after distilling off the solvent from the reaction mixture, pouring the residue into water followed by extraction with a water-immiscible organic solvent and distilling off the solvent from the extract. Additionally, the product can, if desired, be further purified by various well-known techniques, such as recrystallization, reprecipitation or the various chromatography techniques, notably column chromatography or preparative thin layer chromatography.

The process of preparation of a compound of formula (I) of the invention is a further object of the present invention.

According to a first aspect, a compound of the invention of formula (I) can be obtained by reacting a corresponding compound of formula (VII):

by peptidic coupling with a corresponding compound of formula (VIII):

where i, j, k, n, Z, Ri, Rj and Rk are defined as in formula (I), R is H or a halogen and X′ and Y′ are identical to X and Y respectively, or a precursor thereof, or an amino protecting group, optionally followed by alkylation(s) or deprotection as the case may be, respectively.

Said compound of formula (VII) may be obtained by a corresponding compound of formula (VI):

where i, j, n, Z, Ri, Rj are defined as in formula (I), by functionalization.

The Rk group is introduced via convenient functionalization of the keto group which include halogenations, reduction then dehydration, nucleophilic addition followed by dehydration.

The compounds of formula (VI) are novel and are another object of the present invention.

The compound of formula (VI) may be obtained by coupling compounds (II) and (III) or (IV) and (V) according to either of the two pathways below.

First, a condensation between ketones (II) or substituted ketones (IV) is performed with a substituted aniline (III) or (V) leading to the tricyclic acids (VI). Amino terephthalic acids (III) or (V) and the corresponding ketones (II) (pathway I) or (IV) (pathway II) are mixed and stirred in the appropriate solvent. Depending on the reactivity, mixture can be heated or catalysed by the use of acidic conditions. In the case of pathway (II), the reaction is performed via the cyclisation of an intermediate enamine of (IV) and (V).

Further, functionalization of (VI) affords compounds (VII) as acyl halides or carboxylic acids. Peptidic coupling is performed using standard conditions depending on the nature of (VII). Amines HNXY can be either be commercially available or prepared using classical methods prior to coupling to compounds (VII).

An alternative approach was used in the case where —NXY is a diamine. It include the coupling of compounds (VII) with mono-protected—secondary or primary—amines precursor followed by deprotection and one or two successive alkylations using electrophilic reagents such as halides derivatives or aldehydes.

The term “precursor” is used herein to refer to compounds which differ from the indicated or desired compounds by the presence and/or absence of groups or functions. Such groups or functions may be introduced, transformed and/or omitted by common functionalization reactions, known from the skilled person.

The functionalization reaction may be carried out by application or adaptation of known methods.

The above reactions can be carried out by the skilled person by applying or adapting the methods illustrated in the examples hereinafter.

Further, the process of the invention may also comprise the additional step of isolating the compound of formula (I). This can be done by the skilled person by any of the known conventional means, such as the recovery methods described above.

Generally, the starting products (II), (III), (IIV), (V) and (VIII) are commercially available mainly from Aldrich or Acros or other typical chemicals supplier or may be obtained by applying or adapting any known methods or those described in the examples.

According to a further object, the present invention concerns also the pharmaceutical compositions comprising a compound of formula (I) as defined above or a tautomer thereof and/or its pharmaceutically acceptable salts, with a pharmaceutically acceptable excipient.

Preferred embodiments of formula (I) are as defined above in respect of the compounds of the invention.

According to a still further object, the present invention concerns a compound of formula (I) of the invention for inhibiting cysteine protease.

The compounds of the invention are useful for inhibiting cysteine proteases, in particular specific de-ubiquitination enzymes such as USPs, and more particularly USP-7 in patients in the need thereof.

The compounds of the invention are particularly useful for treating and/or preventing cancer and metastasis, more particularly prostate and/or colon cancers, neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, immunological disorders, bone and joint diseases, osteoporosis, arthritis inflammatory disorders, cardiovascular diseases, viral infections and diseases, and/or viral infectivity and/or latency, bacterial infections and diseases.

In particular, said viral infections and diseases are chosen from herpes simplex-1 or -2 viral infections, hepatitis A, hepatitis C, SARS coronavirus infection and disease, Epstein-Barr virus, rhinoviral infections and diseases, adenoviral infections and diseases, poliomyelitis.

According to an aspect, said compounds inhibit one or more viral cysteine proteases.

Bacterial cysteine proteases may be chosen from streptopain, clostripain, staphylococcal cysteine protease, gingipain.

The present invention also concerns the combinations comprising a compound of formula (I) as defined in anyone of claims 1 to 8 or a tautomer thereof, and/or a pharmaceutically acceptable salt thereof,

with one or more active agents chosen from anti-cancer agents, neurological agents, thrombolytic agents, antioxidant agents. anti-infective, anti-hypertensive agents, diuretic agents, thrombolytic agents, immunosuppressive agents, cardiovascular agents, immunomodulatory agents, anti-inflammatory agents, antiviral agents, anti-bacterial agents.

The present invention also concerns the corresponding methods of treatment comprising the administration of a compound of the invention together with a pharmaceutically acceptable carrier or excipient to a patient in the need thereof.

The identification of those subjects who are in need of treatment of herein-described diseases and conditions is well within the ability and knowledge of one skilled in the art. A veterinarian or a physician skilled in the art can readily identify, by the use of clinical tests, physical examination, medical/family history or biological and diagnostic tests, those subjects who are in need of such treatment.

A therapeutically effective amount can be readily determined by the attending diagnostician, as one skilled in the art, by the use of conventional techniques and by observing results obtained under analogous circumstances. In determining the therapeutically effective amount, a number of factors are considered by the attending diagnostician, including, but not limited to: the species of subject; its size, age, and general health; the specific disease involved; the degree of involvement or the severity of the disease; the response of the individual subject; the particular compound administered; the mode of administration; the bioavailability characteristic of the preparation administered; the dose regimen selected; the use of concomitant medication; and other relevant circumstances.

The amount of a compound of formula (I), which is required to achieve the desired biological effect, will vary depending upon a number of factors, including the chemical characteristics (e.g. hydrophobicity) of the compounds employed, the potency of the compounds, the type of disease, the species to which the patient belongs, the diseased state of the patient, the route of administration, the bioavailability of the compound by the chosen route, all factors which dictate the required dose amounts, delivery and regimen to be administered.

“Pharmaceutically” or “pharmaceutically acceptable” refer to molecular entities and compositions that do not produce an adverse, allergic or other untoward reaction when administered to an animal, or a human, as appropriate.

As used herein, “pharmaceutically acceptable excipient” includes any carriers, diluents, adjuvants, or vehicles, such as preserving or antioxidant agents, fillers, disintegrating agents, wetting agents, emulsifying agents, suspending agents, solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents and the like. The use of such media and agents for pharmaceutical active substances is well-known in the art. Except insofar as any conventional media or agent is incompatible with the active ingredient, its use in the therapeutic compositions is contemplated. Supplementary active ingredients can also be incorporated into the compositions as suitable therapeutic combinations.

In the context of the invention, the term “treating” or “treatment”, as used herein, means reversing, alleviating, inhibiting the progress of, or preventing the disorder or condition to which such term applies, or one or more symptoms of such disorder or condition.

“Therapeutically effective amount” means an amount of a compound/medicament according to the present invention effective in preventing or treating a pathological condition requiring the inhibition of an active cysteine protease involved in its pathogenesis.

According to the invention, the terms “patient” or “patient in need thereof”, are intended for an animal or a human being affected or likely to be affected with a pathological condition involving an active cysteine protease in its pathogenesis. Preferably, the patient is human.

In general terms, the compounds of this invention may be provided in an aqueous physiological buffer solution containing 0.1 to 10% w/v compound for parenteral administration. Typical dose ranges are from 1 μg/kg to 0.1 g/kg of body weight per day; a preferred dose range is from 0.01 mg/kg to 100 mg/kg of body weight per day or an equivalent dose in a human child. The preferred dosage of drug to be administered is likely to depend on such variables as the type and extent of progression of the disease or disorder, the overall health status of the particular patient, the relative biological efficacy of the compound selected, the formulation of the compound, the route of administration (intravenous, intramuscular, or other), the pharmacokinetic properties of the compound by the chosen delivery route, and the speed (bolus or continuous infusion) and schedule of administrations (number of repetitions in a given period of time).

The compounds of the present invention are also capable of being administered in unit dose forms, wherein the expression “unit dose” means a single dose which is capable of being administered to a patient, and which can be readily handled and packaged, remaining as a physically and chemically stable unit dose comprising either the active compound itself, or as a pharmaceutically acceptable composition, as described hereinafter. As such, typical total daily dose ranges are from 0.01 to 100 mg/kg of body weight. By way of general guidance, unit doses for humans range from 1 mg to 3000 mg per day. Preferably, the unit dose range is from 1 to 500 mg administered one to six times a day, and even more preferably from 10 mg to 500 mg, once a day. Compounds provided herein can be formulated into pharmaceutical compositions by admixture with one or more pharmaceutically acceptable excipients. Such unit dose compositions may be prepared for use by oral administration, particularly in the form of tablets, simple capsules or soft gel capsules; or intranasally, particularly in the form of powders, nasal drops, or aerosols; or dermally, for example, topically in ointments, creams, lotions, gels or sprays, or via trans-dermal patches.

The compositions may conveniently be administered in unit dosage form and may be prepared by any of the methods well-known in the pharmaceutical art, for example, as described in Remington: The Science and Practice of Pharmacy, 20^(th) ed.; Gennaro, A. R., Ed.; Lippincott Williams & Wilkins: Philadelphia, Pa., 2000.

Preferred formulations include pharmaceutical compositions in which a compound of the present invention is formulated for oral or parenteral administration.

For oral administration, tablets, pills, powders, capsules, troches and the like can contain one or more of any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, or gum tragacanth; a diluent such as starch or lactose; a disintegrant such as starch and cellulose derivatives; a lubricant such as magnesium stearate; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavoring agent such as peppermint, or methyl salicylate. Capsules can be in the form of a hard capsule or soft capsule, which are generally made from gelatin blends optionally blended with plasticizers, as well as a starch capsule. In addition, dosage unit forms can contain various other materials that modify the physical form of the dosage unit, for example, coatings of sugar, shellac, or enteric agents. Other oral dosage forms syrup or elixir may contain sweetening agents, preservatives, dyes, colorings, and flavorings. In addition, the active compounds may be incorporated into fast dissolve, modified-release or sustained-release preparations and formulations, and wherein such sustained-release formulations are preferably bi-modal. Preferred tablets contain lactose, cornstarch, magnesium silicate, croscarmellose sodium, povidone, magnesium stearate, or talc in any combination.

Liquid preparations for parenteral administration include sterile aqueous or non-aqueous solutions, suspensions, and emulsions. The liquid compositions may also include binders, buffers, preservatives, chelating agents, sweetening, flavoring and coloring agents, and the like. Non-aqueous solvents include alcohols, propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and organic esters such as ethyl oleate. Aqueous carriers include mixtures of alcohols and water, buffered media, and saline. In particular, biocompatible, biodegradable lactide polymer, lactide/glycolide copolymer, or polyoxyethylene-polyoxypropylene copolymers may be useful excipients to control the release of the active compounds. Intravenous vehicles can include fluid and nutrient replenishers, electrolyte replenishers, such as those based on Ringer's dextrose, and the like. Other potentially useful parenteral delivery systems for these active compounds include ethylene-vinyl acetate copolymer particles, osmotic pumps, implantable infusion systems, and liposomes.

Alternative modes of administration include formulations for inhalation, which include such means as dry powder, aerosol, or drops. They may be aqueous solutions containing, for example, polyoxyethylene-9-lauryl ether, glycocholate and deoxycholate, or oily solutions for administration in the form of nasal drops, or as a gel to be applied intranasally. Formulations for buccal administration include, for example, lozenges or pastilles and may also include a flavored base, such as sucrose or acacia, and other excipients such as glycocholate. Formulations suitable for rectal administration are preferably presented as unit-dose suppositories, with a solid based carrier, such as cocoa butter, and may include a salicylate. Formulations for topical application to the skin preferably take the form of an ointment, cream, lotion, paste, gel, spray, aerosol, or oil. Carriers which can be used include petroleum jelly, lanolin, polyethylene glycols, alcohols, or their combinations. Formulations suitable for transdermal administration can be presented as discrete patches and can be lipophilic emulsions or buffered, aqueous solutions, dissolved and/or dispersed in a polymer or an adhesive.

The invention is further illustrated but not restricted by the description in the following examples and figures as a non limiting illustration for selective inhibition of USP7 deubiquitinating activity over a panel of active DUBs in physiological conditions.

EXPERIMENTAL

Representative compounds of the invention can be synthesized according to the following procedures.

General Analytical Procedures

NMR spectra were recorded at 300 or 400 MHz for ¹H and at 75 or 100, MHz for ¹³C on a Bruker or Varian spectrometer with CDCl₃ or DMSO-d₆ as solvent. The chemical shifts are given in ppm, referenced to the internal TMS or deuterated solvent signal.

LC-MS analysis was used to analyze and purify target compounds. LC-MS analyses were performed using an Waters Micromass, Bruker Esquire 3000 (ESI-IT) or Agilent Iontrap XCT-Plus mass spectrometers and Waters Alliance 2790 or Agilent 1100 Series LC systems with UV and/or DAD detection. Columns: Waters XTerra MS C18, 30×2.1 mm (3.5 μm), Atlantis T3 C18, 3 μm, 50 mm×2.1 mm or Inertsil C8, 250 mm, 4.6 mm, 5 μm. Flow rates: 0.8-1.2 ml/min, Gradients: a) water 10% MeOH, ammonium formate 10 mM, to 100% MeOH or b) 95% Water-acetonitrile, 0.1% HCOOH to 95% acetonitrile.). UV detection: 190 to 400 nm. All compounds were >95% pure.

General Procedure 1: Preparation of Compounds (VII) Preparation of the Intermediate of Formula (VIIa):

Step 1 Condensation 9-oxo-5,6,7,8,9,10-hexahydro-acridine-3-carboxylic acid (VIa)

To a suspension of 2-amino terephthalic acid (12 g, 6.6 mmols) in diphenyl ether (120 mL), cyclohexanone (25 mL) was added and the reaction mixture was heated to 250° C. for 10 min. Reaction completion was monitored by LC/MS (75% starting material and 25% Product formation was observed). Cyclohexanone (25 mL) was added and the reaction mixture was heated to 250° C. for another 10 min. (LC/MS showed 50% product formation). The above process was repeated till LC/MS showed complete product formation (Starting material<2%). The reaction mixture was cooled to 25° C., product was filtered, washed with hexane (100 mL) and dried under vacuum to get 15.8 g of (Via) (98%) as a yellow solid.

¹H NMR (300 MHz, DMSO) δ 13.27 (s, 1H), 11.54 (s, 1H), 8.14-8.11 (d, 2H, J=8.4 Hz), 7.72-7.70 (m, 1H), 2.72 (m, 2H), 2.44 (m, 2H), 1.76-1.72 (m, 4H).

MS: calcd for C₁₄H₁₃NO₃, 243.09. found 243.8 (M+H)⁺.

Step 2 Halogenation 9-chloro-5,6,7,8-tetrahydroacridine-3-carboxylic acid (VIIa)

A suspension of 9-oxo-5,6,7,8,9,10-hexahydro-acridine-3-carboxylic acid (VIa) (10 g, 4.1 mmols) in phosphorous oxychloride (50 mL) was heated to 100° C. for 1 h. Reaction completion was monitored by TLC. After completion, the reaction mixture was cooled to 25° C. and excess phosphorous oxychloride was removed under vacuum. The residue was mixed with ice (50 g) and the pH was adjusted to 4-5 with solid sodium bicarbonate. The solid obtained was filtered, washed with water (250 mL) and dried under vacuum to get 9.6 g (88%) of compound (Vila) as a white solid.

¹H NMR (300 MHz, DMSO) δ 13.37 (s, 1H), 8.44 (s, 1H), 8.19-8.16 (d, 1H, J=8.7 Hz), 8.09-8.07 (dd, 1H, J=8.7 Hz, 1.5 Hz), 3.06 (m, 2H), 2.96 (m, 2H), 1.99-1.89 (m, 4H).

MS: calcd for C₁₄H1₂ClNO₂, 261.06. found 261.8 (M+H)⁺.

Step 3 Amide Formation

To a 0.1M DMF solution of the heterocyclic acids VII, triethylamine was added (2 equiv.) followed by the corresponding amines (1 equiv.) and coupling agent (TBTU, HATU, OHBT, 1 equiv.). The corresponding mixtures were stirred for 1-12 h at 20° C. Concentrated HCl was added and after 5 min stirring, the mixtures were under vacuum. The crude compounds were extracted with 20 mL d'AcOEt, washed with 10 mL of aqueous 0.5M NaHCO₃ solution and 10 mL of water. The organics phase were dried over MgSO₄ then evaporated under vacuum. Purification using silicagel (gradient CH₂Cl₂ CH₂Cl₂/MeOH 9/1) or preparative LC/MS affords the pure corresponding amides.

Selected data of some of the compounds that were prepared by application or adaptation of the method disclosed above are shown below:

9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid [1-(3-methyl-benzyl)-piperidin-4-ylmethyl]-amide (1)

¹H NMR (400 MHz, DMSO-d₆) δ 8.77 (t, J=5.7 Hz, 1H), 8.47 (d, J=1.8 Hz, 1H), 8.17 (d, J=8.8 Hz, 1H), 8.04 (dd, J=1.7, 8.7 Hz, 1H), 7.36 (s, 1H), 7.18 (t, J=7.5 Hz, 1H), 7.09 (s, 1H), 7.07 (d, J=7.7 Hz, 1H), 7.04 (d, J=7.5 Hz, 1H), 3.38 (s, 2H), 3.32-3.29 (m, 2H), 3.21 (d, J=6.7 Hz, 2H), 3.06 (m, 2H), 2.98 (m, 2H), 2.79 (m, 2H), 2.28 (s, 3H), 1.94-1.84 (m, 6H), 1.69 (s, 1H), 1.66 (s, 1H), 1.63-1.53 (m, 1H), 1.28-1.14 (m, 2H).

MS: calcd for C₂₈H₃₂ClN₃O, 461.22. found 462.17 (M+H)⁺.

9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid [3-(benzyl-ethyl-amino)-propyl]-amide (5)

¹H NMR (400 MHz, DMSO-d₆) δ 8.72 (t, J=5.6 Hz, 1H), 8.43 (d, J=1.7 Hz, 1H), 8.16 (d, J=8.6 Hz, 1H), 8.02 (dd, J=1.7, 8.8 Hz, 1H), 7.29 (m, 4H), 7.18 (m, 1H), 3.54 (s, 2H), 3.32 (m, 2H), 3.06 (m, 2H), 2.98 (m, 2H), 2.46 (m, 4H), 1.89 (m, J=3.73 Hz, 4H), 1.74 (m, J=7.2 Hz, 2H), 0.97 (t, J=7.1 Hz, 3H).

MS: calcd for C₂₆H₃₀ClN₃O, 435.21. found 436.17 (M+H)⁺.

9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid (3-dipropylamino-propyl)-amide (6)

¹H NMR (400 MHz, DMSO-d₆) δ 8.75 (t, J=5.4 Hz, 1H), 8.45 (d, J=1.8 Hz, 1H), 8.17 (d, J=8.8 Hz, 1H), 8.04 (dd, J=1.8, 8.7 Hz, 1H), 3.37-3.28 (m, 2H), 3.06 (m, 2H), 2.98 (m, 2H), 2.44 (t, J=7.1 Hz, 2H), 2.32 (t, J=7.1 Hz, 4H), 1.9 (m, J=3.7 Hz, 4H), 1.68 (m, J=7.0 Hz, 2H), 1.39 (m, J=7.3 Hz, 4H), 0.83 (t, J=7.3 Hz, 6H).

MS: calcd for C₂₃H₃₂ClN₃O, 401.22. found 402.22 (M+H)⁺.

9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid (2-diethylamino-ethyl)-amide (7)

¹H NMR (400 MHz, DMSO-d₆): δ (ppm): 8.69 (t, J=5.7 Hz, 1H), 8.44 (d, J=1.8 Hz, 1H), 8.18 (d, J=8.8 Hz, 1H), 8.04 (dd, J=1.8, 8.7 Hz, 1H), 3.41-3.28 (m, 2H), 3.06 (m, 2H), 2.98 (m, 2H), 2.59 (dd, J=6.8, 8.2 Hz, 2H), 2.52 (q, J=7.1 Hz, 2H), 1.9 (m, J=3.7 Hz, 4H), 0.98 (t, J=7.1 Hz, 6H)

MS: calcd for C₂₁H₂₆ClN₃O, 359.18. found 360.19 (M+H)⁺.

9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid (3-pyrrolidin-1-yl-propyl)-amide (8)

¹H NMR (400 MHz, DMSO-d₆) δ 8.86 (t, J=5.5 Hz, 1H), 8.44 (d, J=1.8 Hz, 1H), 8.17 (d, J=8.8 Hz, 1H), 8.04 (dd, J=1.8, 8.7 Hz, 1H), 3.40-3.28 (m, 2H), 3.06 (m, 2H), 2.98 (m, 2H), 2.50-2.40 (m, 6H), 1.9 (m, J=3.7 Hz, 4H), 1.78-1.64 (m, 6H).

MS: calcd for C₂₁H₂₆ClN₃O, 371.18. found 372.17 (M+H)⁺.

9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid (3-diethylamino-propyl)-amide (10)

¹H NMR (400 MHz, DMSO-d₆) δ 8.8 (t, J=5.5 Hz, 1H), 8.44 (d, J=1.8 Hz, 1H), 8.17 (d, J=8.8 Hz, 1H), 8.03 (dd, J=1.7, 8.7 Hz, 1H), 3.38-3.26 (m, 2H), 3.06 (m, 2H), 2.98 (m, 2H), 2.46 (q, J=7.2 Hz, 5H), 1.90 (m, 4H), 1.68 (m, J=7.0 Hz, 2H), 0.95 (t, J=7.1 Hz, 6H)

MS: calcd for C₂₁H₂₈ClN₃O, 373.93. found 374.19 (M+H)⁺.

Azepan-1-yl-(9-chloro-5,6,7,8-tetrahydro-acridin-3-yl)-methanone (12)

¹H NMR (400 MHz, DMSO-d₆) δ 8.17 (d, J=8.6 Hz, 1H), 7.85 (d, J=1.7 Hz, 1H), 7.6 (dd, J=1.7, 8.6 Hz, 1H), 3.61 (dd, J=5.6, 6.6 Hz, 2H), 3.35-3.28 (m, 2H), 3.05 (m, 2H), 2.98 (m, 2H), 1.89 (m, 4H), 1.76 (m, J=6.2 Hz, 2H), 1.60 (m, 2H), 1.53 (m, 4H).

MS: calcd for C₂₂H₂₃ClN₂O, 342.15. found 343.17 (M+H)⁺.

9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid [3-(4-propyl-piperazin-1-yl)-propyl]-amide (13)

¹H NMR (400 MHz, DMSO-d₆) δ 8.84 (t, J=5.5 Hz, 1H), 8.45 (d, J=1.8 Hz, 1H), 8.17 (d, J=8.8 Hz, 1H), 8.04 (dd, J=1.8, 8.7 Hz, 1H), 3.38-3.28 (m, 2H), 3.06 (m, 2H), 2.98 (m, 2H), 2.36 (m, J=7.0 Hz, 9H), 2.19 (t, J=7.7 Hz, 2H), 1.9 (m, J=4.0 Hz, 4H), 1.71 (m, J=7.0 Hz, 2H), 1.4 (m, J=7.41 Hz, 2H), 0.83 (t, J=7.4 Hz, 3H).

MS: calcd for C₂₄H₃₃ClN₄O, 428.23. found 429.20 (M+H)⁺.

9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid [3-(benzyl-methyl-amino)-propyl]-amide (14)

¹H NMR (400 MHz, DMSO-d₆) δ 8.76 (t, J=5.6 Hz, 1H), 8.44 (d, J=1.8 Hz, 1H), 8.17 (d, J=8.8 Hz, 1H), 8.02 (dd, J=1.7, 8.8 Hz, 1H), 7.33-7.16 (m, 5H), 3.47 (s, 2H), 3.38 (d, J=6.7 Hz, 1H), 3.34 (d, J=6.8 Hz, 1H), 3.33-3.28 (m, 2H), 3.06 (m, 2H), 2.99 (m, 2H), 2.42 (t, J=6.9 Hz, 1H), 2.12 (s, 3H), 1.90 (m, J=3.1 Hz, 1H), 1.77 (m, J=7.0 Hz, 2H).

MS: calcd for C₂₅H₂₈ClN₃O, 421.19. found 422.14 (M+H)⁺.

9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid [3-(4-methyl-piperazin-1-yl)-propyl]-amide (15)

¹H NMR (400 MHz, DMSO-d₆) δ 8.82 (t, J=5.5 Hz, 1H), 8.45 (d, J=1.8 Hz, 1H), 8.17 (d, J=8.8 Hz, 1H), 8.04 (dd, J=1.7, 8.7 Hz, 1H), 3.38-3.28 (m, 2H), 3.06 (m, 2H), 2.98 (m, 2H), 2.36 (m, J=7.0 Hz, 8.5H), 2.14 (s, 3H), 1.9 (m, J=4.1 Hz, 4H), 1.71 (m, J=7.0 Hz, 2H)

MS: calcd for C₂₂H₂₉ClN₄O, 400.20. found 401.20 (M+H)⁺.

Examples Names

-   1 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [1-(3-methyl-benzyl)-piperidin-4-ylmethyl]-amide -   2 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (1-ethyl-pyrrolidin-2-ylmethyl)-amide -   3 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (2-dipropylamino-ethyl)-amide -   4 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [2-(butyl-ethyl-amino)-ethyl]-amide -   5 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [3-(benzyl-ethyl-amino)-propyl]-amide -   6 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (3-dipropylamino-propyl)-amide -   7 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (2-diethylamino-ethyl)-amide -   8 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (3-pyrrolidin-1-yl-propyl)-amide -   9 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [3-(2,6-dimethyl-piperidin-1-yl)-propyl]-amide -   10 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (3-diethylamino-propyl)-amide -   11 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     (2-dimethylamino-ethyl)-amide -   12 Azepan-1-yl-(9-chloro-5,6,7,8-tetrahydro-acridin-3-yl)-methanone -   13 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [3-(4-propyl-piperazin-1-yl)-propyl]-amide -   14 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [3-(benzyl-methyl-amino)-propyl]-amide -   15 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid     [3-(4-methyl-piperazin-1-yl)-propyl]-amide -   16     [1,4′]Bipiperidinyl-1′-yl-(9-chloro-5,6,7,8-tetrahydro-acridin-3-yl)-methanone

Representative Cysteine Proteases USP7 Protein Production & Purification

The cDNA encoding USP7 was obtained by PCR amplification from placenta mRNA. USP7 cDNA was subcloned by PCR into a baculovirus expression vector (pFastBac-HT; Invitrogen). Full-length wild-type human USP7 and its catalytic mutant (cysteine 223 replaced by alanine, C223A) were produced as N-terminally His-tagged fusions in Spodoptera frugiperda cells (Sf9, Invitrogen), using the Bac-to-Bac Baculovirus system from Invitrogen according to the manufacturer's instructions. pFastBac-HT-B-USP7 was used to transform DH10bac cells (Invitrogen), and blue/white selection was carried out on X-gal/IPTG agar plates. Bacmid DNA was prepared by an alkaline lysis procedure. The integrity of the bacmid minipreps and their orientation were checked by PCR, using generic and specific primers. Sf9 insect cells were cultured in InsectXpress medium (Cambrex) at 27° C. and transfected with the corresponding bacmid, using GeneShuttle 40 (Q-BIOgen). Viruses were recovered in the supernatant 72 h after transfection. Viruses were amplified by infecting insect cells (Sf9 or High Five cells; invitrogen) in 50 ml InsectXpress medium in a 150 cm² cell culture flask with 500 μl of the supernatant from transfected Sf9 cells. Following the second round of amplification, infected cells were recovered by rapid SDS lysis, boiled for 5 min at 100° C., sonicated briefly and centrifuged for 20 min at 14,000 g. Expression levels in infected Sf9 cells were compared with those in uninfected cells. Fusion proteins were then allowed to bind to TALON beads (BD Biosciences, TALON metal affinity resin) for 30 min at 4° C. with gentle rocking. Beads were extensively washed (50 mM sodium phosphate buffer pH 7.0, 500 mM NaCl, 10 mM Imidazole, 0.5% Triton X-100 and 10% glycerol) and bound proteins were eluted in wash buffer supplemented with 250 mM Imidazole (Sigma). Eluted fractions were resolved on 4-12% NuPAGE gels (Novex, Invitrogen). Fractions containing high concentrations of purified proteins (purity>95%) were dialyzed (20 mM Tris HCl pH 7.6, 200 mM NaCl, 1 mM DTT, 1 mM EDTA and 10% glycerol) were aliquoted and snap frozen in liquid nitrogen before storage at −80° C.

USP7 Activity Assay

USP7 was diluted in USP buffer (50 mM Tris HCl; 0.5 mM EDTA; 5 mM DTT; 0.01% Triton X-100; Bovine Serum Albumin 0.05 mg·ml⁻¹ pH 7.6). Compounds stocks (10 mM) were stored at −20° C. in DMSO. Compounds were tested at different concentrations: from 200 μM to 91 nM.

Reactions were performed as duplicates in Black 384 well plates (small volumes microplates; Greiner; 10 μl final reaction volume). The substrate concentration for USP7 was 300 nM Ub-AMC (Chem. Biol., 2003, 10, p. 837-846) (Boston Biochem). The concentrations of the enzyme (USP7) in specificity assays was 100 pM. The concentrations were determined in order to perform specificity assays under initial velocities at fixed substrate concentration. Compounds were pre-incubated with enzymes for 30 minutes at 25° C. Reactions were initiated by addition of substrate to the plates containing the enzymes (+/−compounds) diluted in assay buffer. Reactions were incubated for 60 minutes at 37° C. Reactions were stopped by adding acetic acid (100 mM final). Readings were performed on a Pherastar Fluorescent Reader (BMG). λ Emission 380 nm; λ Excitation=460 nm. Data (mean values+/−standard deviation) were analyzed as % of control (no compound) and plotted as percentage versus the Log of the compound concentration using GraphPad (Prism). Data were fitted to a sigmoidal model (variable slope).

USP5 Activity Assay

USP5 was diluted in USP buffer (50 mM Tris HCl; 0.5 mM EDTA; 5 mM DTT; 0.01% Triton X-100; Bovine Serum Albumin 0.05 mg·ml⁻¹ pH 7.6). Compounds stocks (100 mM) were stored at −20° C. in DMSO. Compounds were tested at different concentrations: from 200 μM to 91 nM.

Reactions were performed as duplicates in Black 384 well plates (small volume microplates; Greiner; 10 μl final reaction volume). The substrate concentration for USP5 was 300 nM Ub-AMC (Boston Biochem). The concentrations of the enzyme (USP5) in specificity assays was 300 pM. The concentrations were determined in order to perform specificity assays under initial velocities at fixed substrate concentration. Compounds were pre-incubated with enzymes for 30 minutes at 25° C. Reactions were initiated by addition of substrate to the plates containing the enzymes (+/−compounds) diluted in assay buffer. Reactions were incubated for 60 minutes at 37° C. Reactions were stopped by adding acetic acid (100 mM final). Readings were performed on a Pherastar Fluorescent Reader (BMG). λ Emission 380 nm; λ Excitation=460 nm. Data (mean values+/−standard deviation) were analyzed as % of control (no compound) and plotted as percentage versus the Log of the compound concentration using GraphPad (Prism). Data were fitted to a sigmoidal model (variable slope).

Cloning & Purification of USP8

The cDNA encoding USP8 was obtained by PCR amplification from placenta mRNA. USP8 cDNA was subcloned by PCR into a baculovirus expression vector (pFastBac-HT; Invitrogen). A cDNA encoding a mutated USP8 was generated by mutagenic PCR. The corresponding protein encodes a cysteine to alanine substitution at residue 786. The sequences were ascertained by sequencing of the entire open reading frame. Bacmids encoding USP8 were generated following DH10bac transposition. The corresponding bacmids were transfected into insect cells (Sf9). Viruses were recovered from culture supernatant and amplified twice. Insect cells (Sf9 or High Five; Invitrogen) were infected for 72 hours. Total cell lysates were harvested and lyzed in lysis buffer (Tris HCl 50 mM pH 7.6; 0.75% NP40; 500 mM NaCl; 10% glycerol; 1 mM DTT; 10 mM imidazole; Protease Inhibitor Cocktail; AEBSF 20 μg·ml⁻¹; Aprotinin 10 μg·ml⁻¹). Proteins were affinity purified on metal affinity resins (Talon Metal affinity resin; BD Biosciences). Bound materials were extensively washed in wash buffer (50 mM Sodium Phosphate pH 7.0; 300 mM NaCl; 10 mM imidazole; 0.5% Triton X-100; 10% glycerol) and eluted from the resin in 250 mM imidazole-containing wash buffer. Proteins were dialyzed in dialysis buffer (Tris HCl pH 7.6 20 mM; NaCl 200 mM; DTT 1 mM; EDTA 1 mM; 10% Glycerol). Proteins purifications were analyzed on 4-12% NuPAGE (Invitrogen).

USP8 Activity Assay

USP8 was diluted in USP buffer (50 mM Tris HCl; 0.5 mM EDTA; 5 mM DTT; 0.01% Triton X-100; Bovine Serum Albumin 0.05 mg·ml⁻¹ pH 8.8). Compounds stocks (100 mM) were stored at −20° C. in DMSO. Compounds were tested at different concentrations: from 2001 μM to 91 nM.

Reactions were performed as duplicates in Black 384 well plates (small volume microplates; Greiner; 10 μl final reaction volume). The substrate concentration for USP8 was 300 nM Ub-AMC (Boston Biochem). The concentration of the enzyme (USP8) in specificity assays was 1.36 nM. The concentrations were determined in order to perform specificity assays under initial velocities at fixed substrate concentration. Compounds were pre-incubated with enzymes for 30 minutes at 25° C. Reactions were initiated by addition of substrate to the plates containing the enzymes (+/−compounds) diluted in assay buffer. Reactions were incubated for 60 minutes at 37° C. Reactions were stopped by adding acetic acid (100 mM final). Readings were performed on a Pherastar Fluorescent Reader (BMG). λ Emission 380 nm: λ Excitation=460 nm. Data (mean values+/−standard deviation) were analyzed as % of control (no compound) and plotted as percentage versus the Log of the compound concentration using GraphPad (Prism). Data were fitted to a sigmoidal model (variable slope).

UCH-L1 Activity Assay

UCH-L1 was diluted in USP buffer (50 mM Tris HCl; 0.5 mM EDTA; 5 mM DTT; 0.01% Triton X-100; Bovine Serum Albumin 0.05 mg·ml⁻¹ pH 7.6). Compounds stocks (100 mM) were stored at −20° C. in DMSO. Compounds were tested at different concentrations: from 200 μM to 91 nM.

Reactions were performed as duplicates in Black 384 well plates (small volume microplates; Greiner; 10 μl final reaction volume). The substrate concentration for UCH-L1 was 300 nM Ub-AMC (Boston Biochem). The concentration of the enzyme (UCH-L1) in specificity assays was 2.5 nM. The concentrations were determined in order to perform specificity assays under initial velocities at fixed substrate concentration. Compounds were pre-incubated with enzymes for 30 minutes at 25° C. Reactions were initiated by addition of substrate to the plates containing the enzymes (+/−compounds) diluted in assay buffer. Reactions were incubated for 60 minutes at 37° C. Reactions were stopped by adding acetic acid (100 mM final). Readings were performed on a Pherastar Fluorescent Reader (BMG). λ Emission 380 nm; λ Excitation=460 nm. Data (mean values+/−standard deviation) were analyzed as % of control (no compound) and plotted as percentage versus the Log of the compound concentration using GraphPad (Prism). Data were fitted to a sigmoidal model (variable slope).

UCH-L3 Activity Assay

UCH-L3 was diluted in USP buffer (50 mM Tris HCl; 0.5 mM EDTA; 5 mM DTT; 0.01% Triton X-100; Bovine Serum Albumin 0.05 mg·ml⁻¹ pH 7.6). Compounds stocks (100 mM) were stored at −20° C. in DMSO. Compounds were tested at different concentrations: from 200 μM to 91 nM.

Reactions were performed as duplicates in Black 384 well plates (small volume microplates; Greiner; 10 μl final reaction volume). The substrate concentration for UCH-L3 was 300 nM Ub-AMC (Boston Biochem). The concentration of the enzyme (UCH-L3) in specificity assays was 13 pM. The concentrations were determined in order to perform specificity assays under initial velocities at fixed substrate concentration. Compounds were pre-incubated with enzymes for 30 minutes at 25° C. Reactions were initiated by addition of substrate to the plates containing the enzymes (+/−compounds) diluted in assay buffer. Reactions were incubated for 60 minutes at 37° C. Reactions were stopped by adding acetic acid (100 mM final). Readings were performed on a Pherastar Fluorescent Reader (BMG). λ Emission 380 nm; λ Excitation=460 nm. Data (mean values+/−standard deviation) were analyzed as % of control (no compound) and plotted as percentage versus the Log of the compound concentration using GraphPad (Prism). Data were fitted to a sigmoidal model (variable slope).

Caspase 3 Activity Assay

Caspase 3 was diluted in Caspase 3 buffer (100 mM Hepes pH 7.5; 10% sucrose; 0.1% CHAPS). Compounds stocks (100 mM) were stored at −20° C. in DMSO. Compounds were tested at different concentrations: from 200 μM to 91 nM.

Reactions were performed as duplicates in Black 384 well plates (small volume microplates; Greiner; 10 μl final reaction volume). The substrate concentration for caspase 3 specificity assay was 250 nM (Ac-DEVD-AMC; Promega). The concentration of the enzyme (Caspase 3) in specificity assays was 1.6 nM. The concentrations were determined in order to perform specificity assays under initial velocities at fixed substrate concentration. Compounds were pre-incubated with enzymes for 30 minutes at 25° C. Reactions were initiated by addition of substrate to the plates containing the enzymes (+/−compounds) diluted in assay buffer. Reactions were incubated for 60 minutes at 37° C. Reactions were stopped by adding acetic acid (100 mM final). Readings were performed on a Pherastar Fluorescent Reader (BMG). λ Emission 380 nm; λ Excitation=460 nm. Data (mean values+/−standard deviation) were analyzed as % of control (no compound) and plotted as percentage versus the Log of the compound concentration using GraphPad (Prism). Data were fitted to a sigmoidal model (variable slope).

Cell Viability and Proliferation Methods HCT116 Cell Viability and Proliferation Assay

HCT116 colon cancer cells were obtained from ATCC (American Type Culture Collection), and maintained in Mc Coy's 5A medium containing 10% FBS, 3 mM glutamine and 1% penicillin/streptomycin. Cells were incubated at 37° C. in a humidified atmosphere containing 5% CO₂.

Cell viability was assayed using the MTS technique in 96-well culture plates (CellTiter 96® Aqueous Non-Radioactive Cell Proliferation Assay, Promega) according to the manufacturer's instructions. MTS (3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-sulfophenyl)-2H-tetra-zolium) is a MTT-derived tetrazolium that is reduced in metabolically active cells into a soluble, cell-permeant formazan. The amount of formazan, detected by its absorbance at 492 nm is proportional to the number of living, metabolically active cells.

10³ HCT116 cells were seeded per well. 24 hours later, the medium was changed and the cells treated in triplicate with the concentrations of each compound from 100 μM to 50 nM. The compounds were diluted in 100% DMSO, whose final concentration on cells was kept at 0.5%.

Cells were incubated with the compounds for 72 hours, and their viability then assayed by the addition of MTS for 2 hours. Absorbance at 492 nm was measured directly from the 96-well culture plates. GI50 (Growth Inhibition 50) concentrations for each compound were calculated using a sigmoidal variable slope fit (Prism 4.0, Graphpad Softwares). Values represent mean of three independent experiments.

Methods for Evaluation of Compound Selectivity from a Panel of Deubiquitinatinq Enzymes Active in Cell Lysates

The C-terminally modified vinyl sulfone derivative of ubiquitin, UbVS, was clearly helpful for a direct visualization of active DUBs in cells. This tool, which binds covalently to the cysteine active site of deubiquitinating enzymes, was successfully applied to discover and characterize novel ubiquitin/ubiquitin-like proteases and to profile active deubiquitinating enzymes in normal, virus-infected, and malignant cells (Borodovsky et al., Chem Biol 2002, 9, 1149-1159, Hemelaar et al., Mol Cell Biol 2004, 24, 84-95, Ovaa et al., Proc Natl Acad Sci USA 2004 101, 2253-2258).

The HA-Ub-VS probe (Hemagglutin tag-Ubiquitin-Vinyl Sulfone) was used in this study to directly visualize the activity of all deubiquitinating enzymes from cell lysates. This tool was used to evaluate the activity/specificity of our small molecule compounds on USP7 relative to all deubiquitinating enzymes active in physiological conditions.

Inducible USP7 shRNA HCT116 cells (previously treated with or without Doxycycline (2 μg/ml) for 4 days) as well as HEK293 cells were harvested and lysed on ice with a non denaturating buffer containing Tris pH 7.4, 50 mM; NaCl, 150 mM; MgCl₂, 5 mM; EDTA, 0.5 mM; DTT, 2 mM; ATP, 2 mM; NP40, 0.5% and glycerol, 10%. Samples were incubated at 4° C. for 1 hour and clarified. Proteins were then quantified by Bradford method (Bio-Rad Protein Assay). 25 μg of proteins from native cell lysates were treated with compounds of examples 14 and 5 (from 100 μM to 3 μM) or with NEM (N-Ethylmaleimide, a thiol-reactive compound, 5 mM) for 2 hours at room temperature. The ubiquitin labeling reaction was initiated by the addition of HA-Ub-VS (8 μg/ml) in labeling buffer (Tris pH 7.6, 50 mM; MgCl₂, 5 mM; EDTA, 0.5 mM; DTT, 2 mM; ATP, 2 mM; sucrose, 250 mM) and incubated at room temperature for 30 min. Samples were next heated at 100° C. for 10 minutes and briefly sonicated. They were resolved by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), transferred to a nitrocellulose membrane and probed with antibodies against USP7 (Bethyl Lab, A300-034A), HA (BabCO, MMS-101P), and actin (Sigma, A2066). Horseradish peroxidase (HRP)-conjugated anti-mouse (Jackson Laboratories, 115-035-003) or HRP-conjugated anti-rabbit (Cell Signaling, 7074) antibodies were used as secondary antibodies. Signals were detected by enhanced chemiluminescence (ECL; Amersham) according to the reagent manufacturer's instructions.

Results 1. Selective Inhibition of USP7 Deubiquitinating Activity

The results are summarized on the following table (μM):

Example MW USP7 USP8 USP5 Uch-L1 Uch-L3 Caspase 3 1 462.04 9.1 >200 >200 >200 >200 >200 2 371.91 11.5 >200 >200 >200 >200 >200 3 387.96 12.4 >200 >200 >200 >200 >200 4 387.96 23.5 >200 >200 >200 >200 >200 5 436.00 22.6 >200 >200 >200 >200 >200 6 401.98 23.8 >200 >200 >200 >200 >200 7 359.90 24.9 >200 >200 >200 >200 >200 8 371.91 25.6 >200 >200 >200 >200 >200 9 414.00 28.7 >200 >200 >200 >200 >200 14 421.97 28.1 >200 >200 >200 >200 >200 10 373.93 29.2 >200 >200 >200 >200 >200 11 331.85 29.8 >200 >200 >200 >200 >200 12 342.87 37.9 >200 >200 >200 >200 >200 13 429.01 37.9 >200 >200 >200 >200 >200 15 400.96 43.0 >200 >200 >200 >200 >200 16 411.98 46.0 >200 >200 >200 >200 >200

2. Inhibition of Cell Viability/Proliferation

The results are summarized on the following table (μM):

Cell viability (MTS): HCT116 Gl₅₀ Day 3 Example MW MLogP (μM) 1 462.04 4.5 2.0 2 371.91 3.3 5.0 3 387.96 3.5 3.5 4 387.96 3.5 4.0 5 436.00 4.1 4.0 6 401.98 3.7 3.9 7 359.9 3.0 4.3 8 371.91 3.3 5.9 9 414.00 3.9 3.6 10 373.93 3.3 5.0 11 331.85 2.6 7.8 12 342.87 3.9 20 13 429.01 3.1 5.9 14 421.97 3.9 4.1 15 400.96 2.7 7.4 16 411.98 3.9 13.5

3. Selective Inhibition of USP7 Deubiquitinating Activity Over a Panel of Active Dubs in Physiological Conditions:

As summarized in FIG. 1A, the C-terminally modified vinyl sulfone derivative of ubiquitin (HA-Ub-VS), binds covalently to the cysteine active site of deubiquitinating enzymes. This labeling followed by immunoblot with the anti-HA antibody allowed the identification of all active deubiquitinating enzymes from HCT116 cell lysates (FIG. 1B). In addition, active USP7 was identified in this assay as indicated by the mobility shift observed following immunoblot with anti-USP7 antibody. This labeling, specific to the active form of DUBs, is inhibited by a thiol-reactive compound (NEM) in a non-specific manner (FIG. 1B).

To localize the signal corresponding to active USP7 in the panel of active DUBs following HA-Ub-VS labeling, the inducible shRNA USP7 HCT116 cell line was treated with Doxycycline (Dox) thus enabling the expression of USP7 shRNA. Interestingly, only one band was decreased following USP7 silencing thus clearly indicating that this band corresponds to HA-Ub-VS-USP7 (FIG. 2A). A quantification showing this specific decrease is presented in FIG. 2B (quantification performed using the image analysis software, GeneTools, Syngene). USP7 silencing induced by Doxycycline treatment was confirmed with anti-USP7 antibody.

A study with small molecule compound was first performed with a fixed dose of the compound of example 14 (50 μM) on HCT116 cell lysates. Interestingly, only one band was decreased following treatment at the size corresponding to HA-Ub-VS-USP7 (FIG. 3A). A quantification showing this specific decrease is presented in FIG. 3B (quantification performed using the image analysis software, GeneTools, Syngene). This effect on USP7 activity was confirmed with anti-USP7 antibody as indicated by the mobility shift observed between the treated and non-treated samples.

HCT116 cells were next treated either with different doses of compounds of examples 14 and 5 or with Doxycycline to induce USP7 silencing. Localization of the HA-Ub-VS-USP7 protein was facilitated by the specific silencing of USP7 as indicated in the presence of doxycycline (FIG. 4A, +Dox). Once this band identified, cell lysates were treated with different doses of compounds of examples 14 and 5 and a specific and dose-dependent decrease of the HA-Ub-VS-USP7 protein level was clearly observed (FIGS. 4A and B). This effect on USP7 activity was confirmed with anti-USP7 antibody as indicated by the mobility shift observed between the treated and non-treated samples. Interestingly, these findings were also confirmed in cell lysates prepared from HEK293 cells (FIGS. 5A and B). These results thus demonstrate that different compounds from this new chemical series (compounds of examples 14 and 5) inhibit specifically and dose-dependently USP7 deubiquitinating activity over a panel of active DUBs in physiological conditions. 

1. A compound of formula (I):

wherein: i is an integer chosen from 0, 1, 2 or 3 when n is 1, or from 0, 1, 2, 3 or 4 when n is 2, or from 0, 1, 2, 3, 4 or 5 when n is 3; j is an integer chosen from 0, 1, 2 or 3; k is an integer chosen from 0 or 1; n and n′ identical or different are integers chosen from 0, 1, 2 or 4, provided that 2≦n+n′≦4; Z is CH₂<, —HC<, —N<, NH< or O<; each Ri located on any available position of the A ring is identical or different and chosen from halogen, alkyl, aryl, -alkylaryl, OR, NRR′, CN, CF₃, COR, COOR, CONRR′; each Rj located on any available position of the C ring is identical or different and chosen from halogen, alkyl, aryl, -alkylaryl, OR, NRR′, CN, COR, COOR, CONRR′; each Rk, identical or different, is independently chosen from halogen, alkyl, alkoxy, cyano; X is chosen from H, alkyl, aryl, -alkylaryl, wherein said alkyl and/or aryl is optionally substituted by halogen, alkyl, CN, CF₃, OR, NRR′, COR, COOR, CONRR′; Y is chosen from: (CHT)_(p)NRaRb where Ra and Rb, identical or different, are independently chosen from H, alkyl, aryl or arylalkyl, wherein said aryl is optionally substituted by halogen, alkyl, CN, CF₃, ═O, OR, NRR′, COR, COOR, CONRR′; or Ra and Rb together form with the N atom to which they are attached a N comprising 5 to 7-membered heterocycle which may comprise one or two more heteroatoms chosen from N, O or S, said heterocycle being optionally substituted by one or more of halogen; ═O; alkyl; -alkylaryl or aryl wherein said aryl is optionally substituted by halogen; CN; CF₃; OR; NRR′; COR; COOR; CONRR′; p is an integer chosen from 0 to 6; each T, identical or different is independently chosen from H or alkyl.

 wherein:

 is saturated or partially unsaturated heterocycle or heteroaryl, mono or bicyclic, comprising 1, 2 or 3 heteroatom(s) chosen from N, O or S, optionally substituted by one or more of alkyl; -alkylaryl; OR; C(═O)OR; ═O; CN; CF₃; COR; NRR′; CONRR′; aryl or -alkylaryl wherein said aryl is optionally substituted by alkyl, halogen, OR or COR; q is an integer chosen from 0 to 6; each T, identical or different is independently chosen from H or alkyl. —(CHT)_(r)-aryl wherein: said mono or bicyclic aryl is optionally substituted by one or more of alkyl; OR; CF₃, SO₂NRR′; —C(═O)—R; Halogen; CN; —NRR′; CONRR; C(═O)—Oalkyl wherein said alkyl is optionally substituted by NRR′; and/or said mono or bicyclic aryl is optionally fused with a monocyclic 5 to 7-membered heterocycle; r is an integer chosen from 0 to 6; each T, identical or different is independently chosen from H or alkyl; (CHT)_(s)-(C3-C7)cycloalkyl where s is an integer chosen from 0 to 6; each T, identical or different is independently chosen from H or alkyl; said cycloalkyl is monocyclic, or fused with an aryl; alkyl optionally substituted by CN, Oalkyl; U-S(O)_(t)-alkyl where t is an integer chosen from 0, 1 or 2; -U- is an alkylene optionally substituted by one or more of OR; ═O; CF₃, SO₂NRR′; —C(═O)—R; Halogen; CN; —NRR′; CONRR; C(═O)OR; or X and Y together form with the N atom to which they are attached an heterocycle comprising said N atom and optionally one or two more heteroatoms, said heterocyle being optionally insaturated and/or being optionally substituted by one or more of: ═O; Hal, CN, NRR′, C(═O)alkyl, alkyl; cycloalkyl; heterocycle; C(═O)—Oalkyl; aryl or -alkylaryl where said aryl is optionally fused with an heterocycle and/or said aryl being optionally substituted by alkyl or COalkyl; being optionally fused with an aryl; where R and R′, identical or different are independently chosen from H, alkyl, aryl, -alkylaryl, or a tautomer thereof, and/or a pharmaceutically acceptable salt thereof.
 2. The compound according to claim 1, wherein k=1 and Rk is a halogen.
 3. The compound according to claim 1, wherein n′ is 1 and n is
 2. 4. The compound according to claim 1, wherein: X is defined as in claim 1 and Y is chosen from: (CH₂)_(p)NRaRb where Ra and Rb, identical or different, are independently chosen from H, alkyl, aryl, -alkylaryl, wherein said aryl is optionally substituted by alkyl; p is 0, 1, 2 or
 3. or where Ra and Rb together form with the N atom to which they are attached a 5 to 7 membered heterocycle optionally comprising one or two more heteroatoms chosen from N, O or S, said heterocycle being optionally substituted by one or more of halogen; ═O; alkyl; -alkylaryl or aryl where aryl is optionally substituted by halogen; ═O; CN; CF₃; OR; NRR′; COR; COOR; CONRR′ and; p is chosen from 2 or 3;

 wherein:

 is a saturated or partially unsaturated bicyclic heterocycle or heteroaryl, comprising 1, 2 or 3 heteroatom(s) chosen from N, O or S, optionally substituted by one or more of alkyl; OR; C(═O)OR; aryl or -alkylaryl wherein said aryl is optionally substituted by alkyl, halogen, OR or COR; q is an integer chosen from 0, 1, 2 or 3; each T, identical or different is independently chosen from H or alkyl; (CHT)_(r)-aryl wherein: said aryl is mono or bicyclic, optionally substituted by one or more of alkyl, OR, SO₂NRR′; —C(═O)—R; Halogen; CN; C(═O)—Oalkyl, wherein said alkyl is optionally substituted by NRR′; and said aryl is optionally fused with an heterocycle; r is an integer chosen from 0, 1, 2 or 3; each T, identical or different is independently chosen from H or alkyl; or X and Y together form with the N atom to which they are attached an heterocycle comprising said N atom and optionally one or two more heteroatoms, said heterocyle being optionally insaturated and/or being optionally substituted by one or more of: ═O; alkyl; cycloalkyl; heterocycle; C(═O)—Oalkyl; aryl or -alkylaryl where said aryl is optionally substituted by alkyl; being optionally fused with an aryl, wherein q is 1, 2 or 3, r is 1, 2 or
 3. 5. The compound according to claim 1, wherein: n′=1, n=2 or 3; X is defined as in claim 1 and Y is chosen from: (CHT)_(p)NRaRb where Ra and Rb, identical or different, are independently chosen from H, alkyl, aryl, -alkylaryl, wherein said aryl is optionally substituted by halogen, alkyl, CN, CF₃, OR, NRR′, COR, COOR, CONRR′; or Ra and Rb together form with the N atom to which they are attached a N comprising 5 to 7-membered heterocycle optionally comprising one or two more heteroatoms chosen from N, O or S, said heterocycle being optionally substituted by one or more of halogen; alkyl; -alkylaryl or aryl wherein said aryl is optionally substituted by halogen; ═O; CN; CF₃; OR; NRR′; COR; COOR; CONRR′; p is an integer chosen from 2 or 3; each T, identical or different is independently chosen from H or alkyl; or

 wherein:

 is a saturated or partially unsaturated heterocycle or heteroaryl, mono or bicyclic, comprising 1, 2 or 3 heteroatom(s) chosen from N, O or S, optionally substituted by one or more of alkyl; -alkylaryl; OR; C(═O)OR; ═O; CN; CF₃; COR; NRR′; CONRR′; aryl; wherein said aryl is optionally substituted by alkyl, halogen, OR, COR; q is 1, 2 or 3; each T, identical or different is independently chosen from H or alkyl; or X and Y together form with the N atom to which they are attached an heterocycle comprising said N atom and optionally one or two more heteroatoms, said heterocyle being optionally insaturated and/or being optionally substituted by one or more of: ═O; alkyl; cycloalkyl; C(═O)—Oalkyl; -alkylaryl where said aryl is optionally fused with an heterocycle and/or said aryl being optionally substituted by alkyl or COalkyl; being optionally fused with an aryl; where R and R′, identical or different are independently chosen from H, alkyl, aryl, -alkylaryl.
 6. The compound according to claim 1, wherein n′=1, n=2 or 3; X is chosen from H, alkyl, aryl, -alkylaryl, wherein said alkyl and/or aryl is optionally substituted by halogen, alkyl, CN, CF₃, OR, NRR′, COR, COOR, CONRR′; and Y is chosen from: (CHT)_(p)NRaRb where Ra and Rb, identical or different, are independently chosen from H, alkyl, aryl, -alkylaryl, wherein said aryl is optionally substituted by halogen, alkyl, CN, CF₃, OR, NRR′, COR, COOR, CONRR′; p is 1, 2 or
 3. 7. The compound according to claim 1, wherein: 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid [1-(3-methyl-benzyl)-piperidin-4-ylmethyl]-amide 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid (1-ethyl-pyrrolidin-2-ylmethyl)-amide 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid (2-dipropylamino-ethyl)-amide 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid [2-(butyl-ethyl-amino)-ethyl]-amide 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid [3-(benzyl-ethyl-amino)-propyl]-amide 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid (3-dipropylamino-propyl)-amide 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid (2-diethylamino-ethyl)-amide 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid (3-pyrrolidin-1-yl-propyl)-amide 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid [3-(2,6-dimethyl-piperidin-1-yl)-propyl]-amide 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid (3-diethylamino-propyl)-amide 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid (2-dimethylamino-ethyl)-amide Azepan-1-yl-(9-chloro-5,6,7,8-tetrahydro-acridin-3-yl)-methanone 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid [3-(4-propyl-piperazin-1-yl)-propyl]-amide 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid [3-(benzyl-methyl-amino)-propyl]-amide 9-Chloro-5,6,7,8-tetrahydro-acridine-3-carboxylic acid [3-(4-methyl-piperazin-1-yl)-propyl]-amide [1,4′]Bipiperidinyl-1′-yl-(9-chloro-5,6,7,8-tetrahydro-acridin-3-yl)-methanone or a tautomer thereof, and/or a pharmaceutically acceptable salt thereof.
 8. A compound of formula (VI):

where i, j, n, Z, Ri, Rj are defined as in claim
 1. 9. A pharmaceutical composition comprising a compound of formula (I) as defined in claim 1 or a tautomer thereof, and/or a pharmaceutically acceptable salt thereof, with a pharmaceutical acceptable excipient.
 10. A method for inhibiting a USP comprising administering a compound of formula (I) as defined in claim 1 or a tautomer thereof, and/or a pharmaceutically acceptable salt thereof.
 11. The method according to claim 10 for inhibiting USP7.
 12. A method for treating and/or preventing cancer and metastasis, neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, immunological disorders, bone and joint diseases, osteoporosis, arthritis inflammatory disorders, cardiovascular diseases, viral infections and diseases, and/or viral infectivity and/or latency, bacterial infections and diseases, comprising administering a compound according to claim 1 or a tautomer thereof, and/or a pharmaceutically acceptable salt thereof.
 13. The method according to claim 12, wherein said viral infections and diseases are chosen from herpes simplex-1 or -2 viral infections, hepatitis A, hepatitis C, SARS coronavirus infection and disease, Epstein-Barr virus, rhinoviral infections and diseases, adenoviral infections and diseases, poliomyelitis.
 14. A combination comprising a compound of formula (I) as defined in claim 1 or a tautomer thereof, and/or a pharmaceutically acceptable salt thereof, with one or more active agents chosen from anti-cancer agents, neurological agents, thrombolytic agents, antioxidant agents. anti-infective, anti-hypertensive agents, diuretic agents, thrombolytic agents, immunosuppressive agents, cardiovascular agents, immunomodulatory agents, anti-inflammatory agents, antiviral agents, anti-bacterial agents. 